The Polymerase Chain Reaction (PCR) remains a dominant and highly versatile technology within the companion diagnostics landscape, particularly when rapid, highly sensitive detection of specific point mutations is required for acute treatment decisions. PCR, and its real-time counterpart (qPCR), amplifies minute amounts of target DNA or RNA, allowing for the reliable detection of a mutation even when it is present in only a small fraction of the cells.

In oncology, PCR-based CDx are critical for identifying common, well-defined mutations, such as the BRAF V600E mutation in melanoma or the majority of EGFR mutations in lung cancer. The advantages of PCR include its speed—results can often be generated in hours—its low cost per test compared to sequencing, and its high sensitivity. These characteristics make it ideal for quick turnaround testing in a high-volume clinical setting, where the immediate initiation of targeted therapy can significantly impact patient survival.

The widespread adoption of PCR technology in companion diagnostics has ensured its major market share. In 2024, the PCR segment dominated the market, holding a substantial share, largely due to its high use in common cancer types and its effectiveness in detecting specific mutations. Its continued dominance highlights the need for a range of diagnostic tools, where the appropriate test is chosen based on the speed, sensitivity, and specificity required by the clinical context, supporting the overall market's growth toward $21.1 billion by 2034.

While NGS is growing faster, innovation in PCR is not static. Digital PCR (dPCR), a more advanced variation, is rapidly gaining traction as a high-sensitivity method for detecting resistance mutations in liquid biopsy samples and for monitoring minimal residual disease. dPCR’s ability to provide absolute quantification of targets, even at very low concentrations, is extending the utility of this foundational technology and ensuring its continued relevance in precision oncology.